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Modeling >> Passive Devices >> ASITIC or ADS Momentum
https://designers-guide.org/forum/YaBB.pl?num=1391077213

Message started by AMSA on Jan 30^th, 2014, 2:20am

Title: ASITIC or ADS Momentum
Post by AMSA on Jan 30^th, 2014, 2:20am

Hi guys.

I am new here and I am a newbie with respect this topic, of modelling inductors. I'd like to know if there is someone here that have a tutorial where describes how to model an inductor just to have somewhere to start and explore.

Kind regards.

Title: Re: ASITIC or ADS Momentum
Post by Frank Wiedmann on Jan 31^st, 2014, 12:36am

ASITIC will be much faster but not as precise as ADS Momentum. I suggest you also take a look at the free Sonnet Lite, see http://sonnetsoftware.com/products/lite/, http://www.sonnetsoftware.com/products/lite/2-Turn-Spiral-Inductor-With-Air-Bridge.html and http://www.sonnetsoftware.com/support/lite/getting-started.html.

Title: Re: ASITIC or ADS Momentum
Post by AMSA on Jan 31^st, 2014, 12:58am

Thank you so much for your reply Frank.

In fact, I have heard about sonnet and I've already downloaded it but not tried. I'll install the software and explore a little bit. During my search in this forum I found some threads where there were explained the difference between several types of software that do simulations (3D, 2.5D (like momentum) and so on). Regardless the fact that I am a newbie on this field (modelling inductors), sonnet is a Full EM simulator?

I want to design an inductor for my design (in cadence, microelectronics) and I'd like to optimize the design of the inductor to get the best performance of my circuit and at same time to learn how to model inductors.

Kind regards.

Title: Re: ASITIC or ADS Momentum
Post by Frank Wiedmann on Jan 31^st, 2014, 2:02am

Sonnet is a 2.5D simulator like Momentum. It does a full EM simulation of planar structures.

Title: Re: ASITIC or ADS Momentum
Post by AMSA on Jan 31^st, 2014, 2:39am

Okay. Thank you. I am watching some of the Sonnet IMS Tutorials and I've already read the EM simulation software page from Wikipedia (http://en.wikipedia.org/wiki/EM_simulation_software).

From the list available from Wikipedia, the software that I have heard about were: HFSS, ADS Momentum, ASITIC, FastHenry (despite the fact that I have never used them) and now Sonnet (which I am enjoying watching the tutorials). From what we can observe from the Wikipedia descriptions there is something that came up in my mind: 1st - What is "Mesher"? Looking to the Mesher and the Algorithm column I wonder which one are the most precise/credible in the results?

Taking the advantage of this post, I would like to ask you, if you are some kind of Sonnet guru, one question regarding Sonnet Software.

While watching a tutorial on "RFIC Spiral Inductor Modeling" (which is from my interest), http://www.sonnetsoftware.com/resources/videos/IMS2012/rfic_spiral.html, I didn't understood something.

In minute 6:35 is presented the process stackup and in minute 7:38 how the import of GDSII will be done. In 8:56 the tutor describes in practice what is done. In minute 9:10 the tutor says that the file that he will select contains the stack up configuration from the technology (metal and via characteristics) which is already setup and he says "everything that we want when we create the file by hand in sonnet project", "which is an empty sonnet project".

With this my question is: We have to build that stack up our self? If so, it is only needed to build the corresponding layers that are from our interest (in this case, for example, metal 6 and metal 5)? And the final question how do we build this stack up empty project?

Kind regards.

Title: Re: ASITIC or ADS Momentum
Post by Frank Wiedmann on Jan 31^st, 2014, 4:21am

The process of meshing is pretty well explained in http://www.cfd-online.com/Wiki/Meshing (the differential equations in our case are Maxwell's, of course). I don't think that the type of the mesher tells you very much, it's rather the quality of the algorithm being used that is important.

For the free Sonnet Lite, you don't have much choice for the stackup because you are limited to two metal layers (plus the ground at the bottom of the box). However, even with such a simple setup, you can often represent the real configuration pretty well. How to define the stackup is explained in the manuals and tutorials in the Sonnet Lite distribution.